Bioassay as monitoring system for lead phytoremediation through Crinum asiaticum L.

Abstract

Toxicity of lead in soil is well documented and established. Phytoremediation has gained attention as a cheap, easily applicable, and eco-friendly clean-up technology. Chemical methods are used to assess exact levels and type of pollutants but heavy metal content in soil can also be evaluated indirectly by estimation of phytotoxicity levels using bioassays. Plant bioassays through fast germinating cereals can indicate not only the level of pollution and its effects on growth and survival but also the progress of phytoremediation process. The performance of barley Hordeum vulgare L. seedlings as bioassay for assessment of changes in the levels of lead (Pb) at three concentrations, i.e., 300 (T(1)), 600 (T(2)), and 1,200 ppm (T(3)) in the soil was evaluated while testing the efficiency of Crinum asiaticum L. as a phytoremedial tool. At the first assessment, i.e., 30 DAT (days after treatment) shoot and root lengths of seedlings decreased with increasing concentrations of Pb. As the study progressed, a decrease in levels of Pb was accompanied by better germinability and growth of barley. At 120 DAT seedling growth in all the treatments were comparable to control. In T(1), T(2), and T(3) soils, 74.5%, 83.7%, and 91.2% reduction in lead content was observed at 120 DAT. Highly significant correlations between decreasing pollutant (Pb) content in the soil, seed germination, and seedling growth of barley H. vulgare were found. The differences in root and shoot length as well as overall growth pattern are indicative of the suitability of barley as a bio-monitoring tool.

Genetic Variability of Barley (Hordeum vulgare L.) Genotypes in Phytoremediation of Heavy Metals-Contaminated Soil

“…Some studies were consistent with our results indicating that barley might be a promising phytoremediation crop (Varun et al, 2011;Masu et al, 2012 andGonzález et al, 2017); furthermore, certain genotypes of barley might be used in phytoextraction (Masu et al, 2012); however, adaptability and stability issues need to be considered in this case. On the other hand, other studies suggested that other plant species might be more appropriate for phytoremediation, e.g.…”

“…in grain cereals; however, it is paramount to control accumulation of these micronutrients lower than toxicity levels by inhibiting their excess translocation to grains (Zhao & McGrath, 2009). Barley is a promising candidate as phytoremedial crop because of the strong correlation between its shoots growth and reducing heavy metals in soil (Varun et al, 2011). It can be exploited in phytoremediation of Cr, Cu and Fe; in addition, it has the ability to hyperaccumulate heavy metals in roots (Masu et al, 2012).…”

Metal Contamination of Soils and Prospects of Phytoremediation in and Around River Yamuna: A Case Study from North-Central India

“…Many native, well adapted plants have been investigated and even used for heavy metal bioindicatoring and phytoremedial purposes including lemongrass and other wild grasses, vetiver, Sesbania, Avena, Crotalaria, Crinum asiaticum, Typha latifolia and Calotropis procera etc. [31][32][33][34][35]. Phytoremediation employing indigenous species can be an ecologically viable option for sustainable and cost-effective management.…”

“…Many native, well adapted plants have been investigated and even used for heavy metal bioindicatoring and phytoremedial purposes including lemongrass and other wild grasses, vetiver, Sesbania, Avena, Crotalaria, Crinum asiaticum, Typha latifolia and Calotropis procera etc. [31][32][33][34][35]28]. Native wild species are also important to remediate soils in context of the studied area due to a remark (April, 2006) of the Supreme Court prohibiting the cultivation of plants requiring fertilizers and pesticides along the Yamuna.…”

Abutilon indicum L.: a prospective weed for phytoremediation

“…Even if the soil is naturally high in a particular metal, native plants often become adapted over time to the locally elevated levels so in the case of native flora and soils, metal toxicity issues, mostly, do not arise. Avena, Crotalaria, Crinum asiaticum and Calotropis procera, lemongrass, and other wild grasses have been reported for heavy metal bioindicatoring and phytoremedial purposes (Uraguchi et al 2006;D'Souza et al 2010;Varun et al 2011). Allowing native species to remediate soils is an attractive proposition since a plant community comparable to that existing in the vicinity can be established.…”